Added migration script for old cassettes

tests/fixtures/migration/new_cassette.json

@@ -0,0 +1,31 @@
+[
+    {
+        "request": {
+            "body": null, 
+            "method": "GET", 
+            "headers": {
+                "Accept-Encoding": "gzip, deflate, compress", 
+                "Accept": "*/*", 
+                "User-Agent": "python-requests/2.2.1 CPython/2.6.1 Darwin/10.8.0"
+            }, 
+            "uri" : "http://httpbin.org:80/ip"
+        }, 
+        "response": {
+            "status": {
+                "message": "OK", 
+                "code": 200
+            }, 
+            "headers": [
+                "Access-Control-Allow-Origin: *\r\n", 
+                "Content-Type: application/json\r\n", 
+                "Date: Mon, 21 Apr 2014 23:13:40 GMT\r\n", 
+                "Server: gunicorn/0.17.4\r\n", 
+                "Content-Length: 32\r\n", 
+                "Connection: keep-alive\r\n"
+            ], 
+            "body": {
+                "string": "{\n  \"origin\": \"217.122.164.194\"\n}"
+            }
+        }
+    }
+]

tests/fixtures/migration/new_cassette.yaml

@@ -0,0 +1,15 @@
+- request: !!python/object:vcr.request.Request
+    body: null
+    headers: !!python/object/apply:__builtin__.frozenset
+    - - !!python/tuple [Accept-Encoding, 'gzip, deflate, compress']
+      - !!python/tuple [User-Agent, python-requests/2.2.1 CPython/2.6.1 Darwin/10.8.0]
+      - !!python/tuple [Accept, '*/*']
+    method: GET
+    uri: http://httpbin.org:80/ip
+  response:
+    body: {string: !!python/unicode "{\n  \"origin\": \"217.122.164.194\"\n}"}
+    headers: [!!python/unicode "Access-Control-Allow-Origin: *\r\n", !!python/unicode "Content-Type:
+        application/json\r\n", !!python/unicode "Date: Mon, 21 Apr 2014 23:06:09 GMT\r\n",
+      !!python/unicode "Server: gunicorn/0.17.4\r\n", !!python/unicode "Content-Length:
+        32\r\n", !!python/unicode "Connection: keep-alive\r\n"]
+    status: {code: 200, message: OK}

tests/fixtures/migration/not_cassette.txt

@@ -0,0 +1 @@
+This is not a cassette

tests/fixtures/migration/old_cassette.json

@@ -0,0 +1,34 @@
+[
+    {
+        "request": {
+            "body": null, 
+            "protocol": "http", 
+            "method": "GET", 
+            "headers": {
+                "Accept-Encoding": "gzip, deflate, compress", 
+                "Accept": "*/*", 
+                "User-Agent": "python-requests/2.2.1 CPython/2.6.1 Darwin/10.8.0"
+            }, 
+            "host": "httpbin.org", 
+            "path": "/ip", 
+            "port": 80
+        }, 
+        "response": {
+            "status": {
+                "message": "OK", 
+                "code": 200
+            }, 
+            "headers": [
+                "Access-Control-Allow-Origin: *\r\n", 
+                "Content-Type: application/json\r\n", 
+                "Date: Mon, 21 Apr 2014 23:13:40 GMT\r\n", 
+                "Server: gunicorn/0.17.4\r\n", 
+                "Content-Length: 32\r\n", 
+                "Connection: keep-alive\r\n"
+            ], 
+            "body": {
+                "string": "{\n  \"origin\": \"217.122.164.194\"\n}"
+            }
+        }
+    }
+]

tests/fixtures/migration/old_cassette.yaml

@@ -0,0 +1,18 @@
+- request: !!python/object:vcr.request.Request
+    body: null
+    headers: !!python/object/apply:__builtin__.frozenset
+    - - !!python/tuple [Accept-Encoding, 'gzip, deflate, compress']
+      - !!python/tuple [User-Agent, python-requests/2.2.1 CPython/2.6.1 Darwin/10.8.0]
+      - !!python/tuple [Accept, '*/*']
+    host: httpbin.org
+    method: GET
+    path: /ip
+    port: 80
+    protocol: http
+  response:
+    body: {string: !!python/unicode "{\n  \"origin\": \"217.122.164.194\"\n}"}
+    headers: [!!python/unicode "Access-Control-Allow-Origin: *\r\n", !!python/unicode "Content-Type:
+        application/json\r\n", !!python/unicode "Date: Mon, 21 Apr 2014 23:06:09 GMT\r\n",
+      !!python/unicode "Server: gunicorn/0.17.4\r\n", !!python/unicode "Content-Length:
+        32\r\n", !!python/unicode "Connection: keep-alive\r\n"]
+    status: {code: 200, message: OK}

tests/unit/test_migration.py

@@ -0,0 +1,36 @@
+import filecmp
+import json
+import shutil
+
+import vcr.migration
+
+
+def test_try_migrate_with_json(tmpdir):
+    cassette = tmpdir.join('cassette').strpath
+    shutil.copy('tests/fixtures/migration/old_cassette.json', cassette)
+    assert vcr.migration.try_migrate(cassette)
+    with open('tests/fixtures/migration/new_cassette.json', 'r') as f:
+        expected_json = json.load(f)
+    with open(cassette, 'r') as f:
+        actual_json = json.load(f)
+    assert actual_json == expected_json
+
+
+def test_try_migrate_with_yaml(tmpdir):
+    cassette = tmpdir.join('cassette').strpath
+    shutil.copy('tests/fixtures/migration/old_cassette.yaml', cassette)
+    assert vcr.migration.try_migrate(cassette)
+    assert filecmp.cmp(cassette, 'tests/fixtures/migration/new_cassette.yaml')
+
+
+def test_try_migrate_with_invalid_or_new_cassettes(tmpdir):
+    cassette = tmpdir.join('cassette').strpath
+    files = [
+        'tests/fixtures/migration/not_cassette.txt',
+        'tests/fixtures/migration/new_cassette.yaml',
+        'tests/fixtures/migration/new_cassette.json',
+    ]
+    for file_path in files:
+        shutil.copy(file_path, cassette)
+        assert not vcr.migration.try_migrate(cassette)
+        assert filecmp.cmp(cassette, file_path)  # shold not change file

vcr/migration.py

@@ -0,0 +1,104 @@
+"""
+Migration script for old 'yaml' and 'json' cassettes
+
+.. warning:: Backup your cassettes files before migration.
+
+It merges and deletes the request obsolete keys (protocol, host, port, path)
+into new 'uri' key.
+Usage::
+
+    python -m vcr.migration PATH
+
+The PATH can be path to the directory with cassettes or cassette itself
+"""
+
+from contextlib import closing
+import json
+import os
+import re
+import shutil
+import sys
+import tempfile
+
+
+PARTS = [
+    'protocol',
+    'host',
+    'port',
+    'path',
+]
+
+
+def build_uri(**parts):
+    return "{protocol}://{host}:{port}{path}".format(**parts)
+
+
+def migrate_json(in_fp, out_fp):
+    data = json.load(in_fp)
+    for item in data:
+        req = item['request']
+        uri = {k: req.pop(k) for k in PARTS}
+        req['uri'] = build_uri(**uri)
+    json.dump(data, out_fp, indent=4)
+
+
+def migrate_yml(in_fp, out_fp):
+    migrated = False
+    uri = dict.fromkeys(PARTS, None)
+    for line in in_fp:
+        for part in uri:
+            match = re.match('\s+{}:\s(.*)'.format(part), line)
+            if match:
+                uri[part] = match.group(1)
+                break
+        else:
+            out_fp.write(line)
+
+        if None not in uri.values():  # if all uri parts are collected
+            out_fp.write("    uri: {}\n".format(build_uri(**uri)))
+            uri = dict.fromkeys(PARTS, None)  # reset dict
+            migrated = True
+    if not migrated:
+        raise RuntimeError("migration failed")
+
+
+def migrate(file_path, migration_fn):
+    # because we assume that original files can be reverted
+    # we will try to copy the content. (os.rename not needed)
+    with closing(tempfile.TemporaryFile()) as out_fp:
+        with open(file_path, 'r') as in_fp:
+            migration_fn(in_fp, out_fp)
+        with open(file_path, 'w') as in_fp:
+            out_fp.seek(0)
+            shutil.copyfileobj(out_fp, in_fp)
+
+
+def try_migrate(path):
+    try:  # try to migrate as json
+        migrate(path, migrate_json)
+    except:  # probably the file is not a json
+        try:  # let's try to migrate as yaml
+            migrate(path, migrate_yml)
+        except:  # oops probably the file is not a cassette
+            return False
+    return True
+
+
+def main():
+    if len(sys.argv) != 2:
+        raise SystemExit("Please provide path to cassettes directory or file. "
+                         "Usage: python -m vcr.migration PATH")
+
+    path = sys.argv[1]
+    if not os.path.isabs(path):
+        path = os.path.abspath(path)
+    for root, dirs, files in os.walk(path):
+        for file_name in files:
+            file_path = os.path.join(root, file_name)
+            migrated = try_migrate(file_path)
+            status = 'OK' if migrated else 'FAIL'
+            sys.stderr.write("[{}] {}\n".format(status, file_path))
+    sys.stderr.write("Done.\n")
+
+if __name__ == '__main__':
+    main()